The MET matrix shows used materials (M), consumed energy (E) and generated toxicity (T) in the different stages of the product life cycle.

This systematic method for the organisation of relevant environmental information related to the product allows the identification of strengths and weaknesses. The basic MET matrix structure is shown in the table below. More information about the specific contents of the matrix can be found in the attached document, which will help you in its completion.

	Materials	Energy	Toxic emissions
Materials and components production
Production
Distribution
Operation (normal functioning)
Service (maintenance and repairs)
Waste management

The information included in the Matrix should be quantitative whenever possible, or qualitative if data is not available. The time that it takes you to fill in the matrix depends on the complexity of your product and the availability of data about its life cycle.